The present invention relates generally to ordnance fuzes and more particularly to the explosive-train, arming-rotor type fuze having a dual, out-of-line safe position and providing armed-safe indications.
The function of explosive-train, arming-rotor ordnance fuzes is to keep the readily-initiated detonator separated from the less sensitive booster charge when a fuze or weapon is being stored or handled to avoid premature detonation if the weapon is subjected to an unusual environment or to rough handling.
Various fuzes having rotatable or slidable arming rotors or interrupter have been devised, but they lack the reliability, safety, and armed-safe indication that is desired. For example, the arming rotor in the safety and arming devices forms or contains a component of the explosive train, and in the safe position is held out-of-line, either axially or rotationally. The fuze is then armed by physically aligning the rotor by means of an escapement mechanism activated by a timer, triggered upon ordnance deployment and powered by some form of stored energy, such as a wound spring. The presence of the stored energy is a definite safety hazard, and the arming rotor, with its single, out-of-line safe position can easily be accidently displaced into its armed position. Therefore, for reasons of safety, it is necessary to keep the fuzes separated from the weapons during transportation and handling operations and in storage, rather than being assembled at the manufacturing stage, to avoid possible disasters.
Frequently the weapons would be roughly handled when a ship was provisioned and when a gun or an aircraft was loaded with the weapons. Occasionally, weapons would be subjected to fire and excessive heat. Since existing fuzes are not entirely reliable, they therefore had to be assembled to the weapon in the field, an often difficult task, resulting in loss of time and unnecessary exposure of personnel.
Another consideration for keeping the fuzes and weapons separated until use is that frequently there are no positive indications of the fuze's safe or armed condition when it was installed in the weapon. The armed-safe condition is generally determined by observing the interrupter or a "flag" through a viewing window, but this may be difficult under red-light battle conditions aboard ship. Frequently the armed-safe indicator is concealed, or at best difficult to see, when the fuze is installed on the weapon.
Often indicators did not exist in prior art fuzes, and it was impossible to determine if they were armed or safe, or if they had been poorly assembled or were missing vital parts, except by inspection at the time of assembly or by x-ray techniques later.